Ambulatory medical infusion pumps are a commercially successful and popular medical instruments. The pumps allow for the convenient continuous and calibrated delivery of a variety of medicines including but not limited to antibiotics, pain relieving drugs, and chemotherapy drugs.
The pump has a fastener system that allows a supply tube to be removably attached to the pump. The supply tube can be installed on a cassette that has a soft pliable drug reservoir bag placed within a hard shell made from a rigid plastic such as a poly-carbonate to protect the integrity of the bag. The supply tube has a soft section positioned within the pump assembly which is squeezed between the pump and the cassette pump plate to draw or pump the medicine through the supply tube.
The soft tube section is attached to microbore tubing that exits the pump assembly. The microbore tubing has a luer lock or similar connector attached to its distal end that allows connection to a intravenous infusion or subcutaneous delivery system. The microbore tubing resists any unintentional kinking or crimping thus assuring proper delivery of the drugs therethrough.
The pump plate of the pump cassette is permanently secured either by adhesive or sonic welding to the cassette shell to assure that the shell is not unintentionally removed from about the bag so that the bag does not become accidentally exposed and maintains its integrity against accidental puncture.
Often larger amounts of medicine are needed by the patient. Instead of using numerous cassettes with a small bag in each cassette, a larger remote bag of medicine is used. The cassette that attaches to the pump includes only a soft supply tube that engages the pump, a microbore outlet tube that attaches to the patient and a microbore inlet tube that attaches to the remote bag. The inlet tube and outlet tube have distal ends permanently attached to fittings such as luer locks. The fittings maintain the tube assembly permanently secured to the cassette. The microbore tubes are permanently connected to opposing ends of the soft supply tube. The cassette is constructed to permanently retain the supply tube in place. This cassette assembly is often referred to as a remote reservoir cassette or remote cassette.
When the medicine needs to be changed, one supply bag is easily disconnected from the pump cassette and a second medicine in another supply bag is conveniently attached to the pump cassette.
Because the supply tube has been in fluid contact with a patient, the used cassette tubing and or reservoir bag may contain bodily fluids that passed up though the tubing. Thus, the tubing and or reservoir bag are considered medical waste and must be disposed of accordingly. Many principalities now have laws that forbid medical waste from being placed in landfills. The preferred disposal method is by incineration. For proper incineration, the entire cassette with both the used tubing and reservoir bag along with the cassette shell need to be incinerated at relatively high temperatures compared to regular incineration temperatures of other waste products. Similarly, the remote cassette along with used tubing need to be incinerated at high temperature. The higher temperatures are needed for the proper decomposition of certain chemotherapy drugs and for certain rigid plastics such as poly-carbonate. The entire cassette has been incinerated even though the cassette shell can be easily re-sterilized and capable of being used again because the cassette is made to permanently retain the tubing and reservoir bags and it is too difficult and expensive to break into the cassette, cut the tubing and rebuild the cassette with a new bag and tubing in place.
The pumps are constructed for long durability. A typical cassette containing a reservoir bag is capable of holding only one hundred milliliters (100 ml.). The pump thus can pump many cassettes each day as needed. The pump during its useful life can be used with many thousands of cassettes over several years.
The increasing expense and difficulties of proper disposal of the cassette assembly necessitates that only the waste be disposed of and other parts be repaired and reused when possible and convenient. The re-use of the cassette shell can save much plastic and reduce the amount of unnecessary incineration and the unwanted particulates and gasses produced by incineration.
What is needed is a cassette shell and pump plate that allow for easy removal of tubing and reservoir bags and easy reinstallation of replacement supply tubes and reservoir bags without the need for drilling, cutting or tearing of the cassette, bags, or tubing thus reducing the exposure of the fluids to the exterior. What is needed is a recyclable cassette that allows the bags and tubes to remain closed until proper incineration.